1. Field of Invention
This invention relates to diagnosing systems. In particular, this invention relates to systems and methods for diagnosing systems using a hybrid diagnostics technique.
2. Description of Related Art
Current electronic systems, such as printers and photocopiers, run until a failure occurs. Upon occurrence of one or more failures in the machine, a dedicated sensor in the machine will display an error message on, for example, a user interface indicating a monitored component has failed. This error message contains general information pertaining to the failed monitored component. Based on the content of this error message, a user can either attempt to perform a repair themselves or contact, for example, a customer service engineer to initiate a service call on the machine.
The above systems work well for sensed components. However, the above systems are incapable of determining which component has failed if the failed component is not a monitored component. Additionally, the above systems recognize failures after they occur and are not capable of dynamically diagnosing failures, or potential failures, in real time. Accordingly, service time is increased, service costs increased and machine down-time increased, all of which lead to customer dissatisfaction.
This invention provides systems and methods that use a combination of qualitative model based reasoning and quantitative analysis techniques in a hybrid diagnostic scheme for diagnosing and/or predicting the status of one or more components in electronic system(s). The quantitative schemes are based on analysis of machine data received from, for example, traditional monitoring devices. This hybrid diagnostic scheme allows for diagnosis and prediction down to the individual component level, with little or no additional sensors beyond those required for normal operation of the machine. This hybrid technology allows an electronic system the ability to self-diagnose itself, for example, in operation as customer jobs are being run, in an effort to, for example, reduce service costs, increase machine up-time and improve customer satisfaction. Alternatively, the systems and methods of this invention can be used at any stage of the manufacturing process or life of the machine to aid in diagnosing failures down to, for example, the individual component level, which may or may not be a directly monitored component.
The systems and methods of this invention combine a qualitative discrete event systems diagnostic methodology in conjunction with quantitative analysis methodologies to achieve a hybrid diagnostic scheme that can perform real-time failure diagnosis and prediction.
This invention separately provides systems and methods that use a combination of qualitative model based reasoning and quantitative analysis in a hybrid diagnostic scheme to diagnose document processing systems such as printers, photocopiers, scanners, facsimile machines, or the like.
The diagnostic systems and methods of this invention enable the design and production of intelligent self-diagnosing machines. Specifically, the diagnostic systems and methods of this invention monitor and track signal changes in one or more machine components. This monitoring can occur in real-time or at some other predetermined or user selected interval. The monitoring may also occur in the normal operational mode of the device or, in a special diagnostic mode.
The systems and methods of this invention utilize a diagnosis methodology that monitors the operation of one or more systems by looking at xe2x80x9ceventsxe2x80x9d occurring in a system, such as, for example, commands, control signals, sensor readings, high to low signal transitions, test results, fault flags, counters, parameter changes, and the like. Based on the occurrence of these events, the diagnosis system can generate estimates of the state of the system, and from the state estimates infer the current operational status of the system, such as a fault.
Since the diagnostics systems and methods of this invention are based on a hybrid approach to diagnosis, the diagnostics system are capable of coping with multiple sources of diagnostic information and assessing the state of the machine based on one or more monitored signal changes and additional information, derived from, for example, one or more virtual sensors. Thus, the diagnostic system is not limited to the number of sensors and/or virtual sensor inputs. The use of virtual sensors in the systems and methods of this invention supplement machine sensors and aid in enabling unique component level diagnosis of a machine while reducing or eliminating the need for installation of additional sensors.
Thus, the diagnosis system is capable of dynamic tracking of one or more systems and the ability to reason with multiple sources of information, such as sensors, virtual sensors and indicators. Furthermore, the diagnostic system is capable of identifying a machine""s status, for example, a failure, a suspected failure, or a predicted failure at least down to the failed component, such as a field replaceable unit or a customer replaceable unit.
In particular, at least one of a system controller, system sensor and virtual sensor forward information from one or more systems, or, additionally, sub-systems, to an event generator. The event generator compiles the information from the one or more systems, controllers sensors, and/or virtual sensors, and generates an xe2x80x9ceventxe2x80x9d based on the received information. This xe2x80x9ceventxe2x80x9d is then forwarded to a diagnosis system. The diagnosis system, analyzing the events, can then estimate the state of the system, for example, based on a finite state machine model of the one or more components in the system, a constraint based model of the system, a rule based system, or the like. The estimated state, which reflects the status of the system, such as, for example, normal status, a failure mode, or predicted failure mode, can then be output to one or more output devices. Furthermore, information pertaining to the system status can be forwarded to at least one or more of a user, a system operator, service and customer support entities, an autonomous repair agent, a collocated or remote destination, or a distributed network, such as that described in co-pending Attorney Docket No. 103244, incorporated herein by reference in its entirety.
Thus, the hybrid diagnosis systems and methods of this invention are capable of providing a xe2x80x9cfront-endxe2x80x9d to, for example, a diagnostic server, which can in turn determine an appropriate action for the transmission of specific data types directly or indirectly to one or more of a customer, autonomous repair agent, service provider and/or part/consumable supplier, and/or notify the appropriate assistance, repair, parts and/or suppliers to provide the system(s) which is predicted to fail, or has failed, the appropriate information or parts to repair or service the machine.
These and other features and advantages of this invention are described in or are apparent from the following detailed description of the preferred embodiments.